Insulated wires are used in myriad applications. For instance, insulated wires may be used to create electromagnetic devices, such as motors. In particular, the wires can be wound around a magnetic core so that when current flows through the wires, a magnetic field is created to cause the core to move and produce a force. In other applications, the insulated wires may be used as part of a sensor, such as a linear variable differential transformer. Here, the wires make up a primary winding and a secondary winding that together define a coil assembly including an axial bore, and a magnetic core is disposed in the axial bore. The magnetic core moves axially within the axial bore and causes a differential current flow through the secondary winding.
Typically, the insulated wires are made from a conductive material that is coated with an electrically insulating material. The insulating material may be polyimide, polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC) or another suitable material offering electrically insulative properties. These materials are applied to the wire via a spraying, drawing or electrolytic process. Polyimide insulated wires are relatively inexpensive and simple to manufacture and operate sufficiently under most circumstances. However, they have an upper continuous working temperature limit of about 240° C. In cases in which the insulated wires are exposed to temperatures greater than 240° C., the polyimide insulated wires are disposed in a protective housing, or are replaced with other types of insulated wires, such as PTFE-coated wires. PTFE can be used to increase the operating temperature to a working temperature of 260° C., but has a maximum excursion temperature near 300° C. Other insulating materials characterized by good dielectric properties, such as silicon oxides, may have temperature stability but cannot be bent or formed after the insulative material has been created. Thus, use of these types of insulated wires may be limited to applications in which space constraints are not a concern, where temperature can be controlled or where the wires can be formed and cured in the final application.
Accordingly, it is desirable to have an insulated wire that may be used in relatively high temperature environments (e.g., greater than about 240° C.) and may be bent into a desirable shape at any time after being coated with the insulation. Furthermore, other desirable features and characteristics of the inventive subject matter will become apparent from the subsequent detailed description of the inventive subject matter and the appended claims, taken in conjunction with the accompanying drawings and this background of the inventive subject matter.